Flash and SRAM

 Hi,

Every embedded firmware engineer shall know a fundamental that, what goes to which area.

In this blog I will be touching two things one is Flash and SRAM.

So, what will be placed into SRAM and which part of the code written by us goes into the Flash area of MCU.

Consider below example code

unsigned int gl_Count = 0;

void get_count (void)

{

    return gl_Count;

}

void increment_count(void)

{

    gl_Count++;

}

In the above code when we declare a variable globally then that will be placed into SRAM and that is not placed into Flash. There might be some compiler constructs which might allow you to do so. However in this case there are no constructs hence the gl_Count will be allocated from SRAM.

Where as the funciton get_count and increment_count will be placed in the Flash space of the MCU.

When we implement / write a code, that will be placed in the Flash Area of the Microcontroller.  After writing the code it shall be cross compiled so that the generated output can be burned into the MCU's Flash using an external programmer / JTAG.

Hope this helps.